Broaching machine



June 11, 1940.

E. D. VANCIL ET AL BROACHING MACHINE Filed May 22, 195'! 4 Sheets-Sheet 1 FIG. 2

INVENTOR. EDGAR D. M4NC/L BY AMOSHHAWLE) 2 ATTORNEY.

E. D. VANClL ET AL June: 11, 1940.

BROACHING MACHINE Filed May 22, 1957 4 Sheets-Sheet 2 INVENTOR. EDGAR D. IA NC/L AMasH HA ATTORNEY.

June 11, 1940. E. D. VANClL ET AL BROACHING MACHINE Filed May 22, 1937 4 Sheets-Sheet 3 INVENT OR. EDGAR D. M4/vc/L BY AMOS H HA WLE) We/1m- ATTORNEY.

June I], 1940.

E. D. VANCIL ET AL 2,203,803

BROACHING MACHINE Filed May 22, 1937 -4 Sheets-Sheet 4 START INVENTOR. EDGAR D l A/vc/L BY AMos H. HAWLEY wi m ATTORNEY.

Patented June 11, 1940 UNITED STATl-ZS PATENT OFFICE nnodonmc MACHINE Edgar D. Vancil and Amos H. Hawley, Sr., Cincinnati, Ohio, assignors to The Cincinnati Milling Machine Company, Cincinnati, Ohio, a corporation of Ohio Application May 22, 1937, Serial No. 144,192,

18 Claims. (Cl. arr-33 r.

This invention relates to improvements in automatic broaching machines.

One of the objects of this invention is to provide an automatic broaching 'machine having' improved work translating and positioning valve; and the annular space between the tubes means; is connected by a channel 24 to port 25 of the Another object of this invention is to provide ram controlled valve 26. It should be apparent an improved automatic single ram broaching that by alternately admitting fluid to channels machine. I 22 and 24 and connecting the remaining channel A further object of this invention is to provide to reservoir that 'the broaching ram may be an improved hydraulic operating and control caused to move up and down. circuit for automatic broaching machines. The table I2 is supported on horizontal guide- Other objects and advantages of the present ways 21 as more particularly shown in Figure 2, invention should be readily apparent by reference for movement in a plane at right angles to the i to the following specification considered in conplane of movement of the'broaching ram. In L junction with the accompanying drawings illusother words, while the broaching ram is at the trative of one embodiment thereof, but it will be upper limit of its stroke, the table l2 may be' understood that any modifications may be made advanced to position a, work piece in the path in the specific structural details within the scope of the broaching tools and while held in a preof the appended claims without departing from scribed position, the broaching ram may be or exceeding the spirit of the invention. moved downward to effect a cutting operation.

Referring to the drawings in which like refer- After the operation has been completed, the table ence numerals indicate like or similar parts: I2 is returned to move thework out of the path Figure l. is an elevation of a broaching maof the broaching tools, and the ram itself is chine embodying the principles of this invention. raised to its starting position. 25

Figure 2 is an elevation of the machine shown Means have been provided whereby the table in Figure 1 as viewed from the right end of that I2 is advanced and retracted automatically with figure. respect to some prescribed working position so Figure 3 is an enlarged sectional view taken that the operators duties are :reduced to simply on the line 3- -3 of Figure 1 and showing the deloading and unloading the machine, and starting tails of the table operating mechanism. the machine after each cycle if the machine is Figure 4 is an enlarged view taken on the line operating on the single cycle method. 4--4 of Figure 1, with certain portions in sec- To this end the table has integrally formed. tion, showing the trip controlled mechanism therewith, as shown in Figures 3 and 5, a cylinoperated by the table. der 28, and this cylinder contains a. piston 29 Figure 5 is a diagrammatic view of the hywhich is connected by a double tubular piston draulic control circuit. a rod 30 to a fixed part 3| of the machine. The

Referring to Figures 1 and 2 of the drawings, piston rod hasan inside tube'32 through which the reference numeral l0 indicates the column fluid is admitted to one end 33 of the cylinder to of a broaching machine, upon which is slidably cause advance of the table to a broaching posimounted in suitably formed guideways, a broachtion; and an annular space 34 between the inner ing ram II, which is adapted to have a series of tube and the outside tube 35 for admitting fluid broaching tools attached thereto for movement to the other end 36 of the cylinder for causing relative to a work supporting table l2. retraction of the table.

The ram II has a cylinder I3 integrally forme As shown in Figure 3, the piston rod 30 has a therewith, and contained in this cylinder is a lost motion connection with the fi d Da t 3| of piston M which is connected by a double tubular the machine. In other words, the extreme end piston rod [5 to a fixed part l6 of the machine. of the piston rod is provided with an enlarged By means of this arrangement the cylinder is the head 31 which forms a shoulder 38 engageable moving element, and the piston, the fixed elewith one side 39 of an abutment portion 40. The

ment. By means of the double tubular piston rod it is possible to cause fluid to flow between the inside tube I1 and the outside tube IE to the upper end IQ of the cylinder, the outside sleeve having radial holes or passages 20 drilled 2| of the cylinder.

therein near one face of the piston. The inner tube l'l serves to convey fluid to the lower end The tube I1 is connected by-a channel 22 to port 23 of the ram controlled The lever 4| is part of a bell crank 42 which has a second arm 43, the end of which is bifurcated, as more particularly shown in Figure 4, for engagement with slots 44 cut in opposite sides of a block" 45 integral with the piston rod. In the position of the parts shown in Figure 3, the work table I2 is in a cutting position and the lever 4| is in a locking position. It will be evident that upon admission of fluid pressure to the chamber 36 of cylinder 28 that the piston 29 will move toward the right until the lost mo tion existing between the head 31 and the shoulder 39 is taken up. This movement will be sumcient to rotate the bell crank clockwise through a sufiicient angle to cause the end of the lever 4| to clear the abutment 46 which is integral with the table. With the locking leverwithdrawn and the piston 29 held against further movement by the abutment 39, .the fluid pressure is now able to cause retraction of the table l2.

Upon reversal of pressure in cylinder 28!, or in other words, upon admittance of fluid pressure to chamber 33 of the cylinder, the piston 29 will be urged toward the left asviewed in Figure 3 because it is freer to move than the table, but this movement will be prevented to a large extent for the present because the abutment 46 is now positioned over the top 'of the lever 4| having been pair of spaced abutments 4'! which are in line with a pair of adjustable stops ,48 carried by the table. Each of these adjustable stops consists of a belt which is threaded into the end of the table and locked in position by a lock nut 58. 'It

will now be apparent that pressure in the chamber 33 is urging the table forward against the positive stops which react in such a way as to cause the piston 29 to move toward the left and thereby urge thebell crank in a counterclockwise direction into locking position until the angular surface 5| on the abutment 46 prevents further rotation of the bell crank. The table is thus locked against movement in either direction.

The block 45 forming part of the piston rodhas a depending portion 52 through which two holes are drilled forming part of channels 53 and 54 by which the cylinder'is. connected to the control valve. It will be noted that the channel 53 in Figure 3 terminates in an angular portion which intersects the annular space 34 existing between the outside tube 35 and the inside tube 32. Since this annular space does not continue through the block 45, the channel 54 may continue straight whereby it will intersect an annular groove 55 formed in the block as more particularly shown in Figure 4. The end of the inside tube 32 is provided with drilled holes 56 adjacent this portion to effect hydraulic-connection to the inside of tube 32.

Although the block 45 and the dependent portion 52 are rigid with the piston rod and move with it, metal tubes can still be utilized to form the connecting portions of channels 53 and 54 with the control valves by forming the connecting tubular portions in the shape of a U.

The channel 53 terminates in port 51 of the ram controlled valve 26, and the channel 54 terinmates in two ports, one of them being part 58 of the ram controlled valve and the other being port 59 of the table controlled valve 68.

The plunger 6| of the ram controlled valve is shifted by hydraulic pressure under the control of apilot valve 62. This pilot valve has a shiftable plunger 63 which has two positions and is normally held in either one of these two positions by a spring pressed detent 64 engageable with detent notches 65 cut in the periphery of the plunger. This valve has a pressure port 66 which is supplied with fluid by a constant displacement or metering pump 61 through channel 68. It also has a pair of ports 69 and 18 which are connected by channels H and 12 respectively to opposite ends of the valve housing 26. An additional pair of ports 13 and 14 of the pilot valve are connected to the exhaust or return line 15 which has a low pressure check valve 16 therein for maintaining the lines full of fluid. It will be noted that a central spool ,18 formed on the plunger 63 is larger in diameter than the shoulders l1 and I9, whereby the valve becomes a selfactuating valve. In other words, after the spool 18 passes pressure port 66, the 'fluid entering the annular groove on either side of the spool will produce unequal resultant pressures axially of the valve plunger and will continue the movement of the'plunger in the direction in which it is moving thereby operating in the manner of a load-and-fire mechanism.

The plunger 63 is shifted by dogs carried by the broaching ram, and to this end the plunger is provided with an enlarged head 88 which has annular beveled surfaces 8| and 82 formed on opposite sides thereof. A trip dog 83 carried by the ram has a V-shaped projecting head 84 which is adapted to engage the beveledsurface 82 on the head of the plunger to shift the same to the left as viewedin Figure 5. The ram also carries a second dog 85 which has a V-shaped head .engageable with a beveled surface on the end of the plunger forshifting the same toward the right as viewed in-Flgure 5. Thus the pilot valve is shifted from one extreme position to the other at each end of the stroke of the broaching ram.

The valve plunger 86 of the table controlled valve 68 is also hydraulically shifted and this shifting is under the control of a second pilot valve 8l having a plunger 88. This plunger has an enlarged central spool 89 on the opposite sides of which are annular grooves 98 and 9| which terminate in shoulders 92 and 93 respectively which, as shown in the drawings, are smaller in diameter than the spool 89 whereby the valve becomes a self actuating valve. The valve 81 is provided with a pressure port 94 which is supplied with fluid from the pump 68 through a branch 95 of channel 68. On opposite sides of the pressure ports are a pair of ports 96 and 91 'which are connected by channels 98 and 99 respectively to opposite ends of the table controlled valve 68. In addition, a pair of exhaust ports I88 and IN formed in the pilot valve are connected by branch I82 to the return line 15. It will now be evident that when the valve plunger 68 is in one position, such as that shown in Figure 5, the pressure port 94 is connected to channel 98 and the valve plunger 86is shifted to the right; and when 'the port'94 is connected to channel 99, the plunger 86 is shifted to the left.

As shown in Figure 4, the valve plunger 88 is pr vided with a detent mechanism comprising I04 formed in the periphery of the plunger. This plunger is shifted by a pair of dogs I05 and I06 by engagement with beveled surfaces I01 and I08 respectively formed on opposite sides of an enlarged head I09 integral with the valve plunger. The dog I08 is carried by the locking lever H, as shown in Figure 3, and the dog I05 is carried on the under side of the table being adjustably mounted in a T-slot IIO and clamped in position by a T-bolt III.

A start and stop valve H2 is provided in the main circuit, and it has a valve plunger 'II3 which may be manually shifted to any one of three positions, the central position being a stop position. The valve is also hydraulically shifted from its start or normally running position to its stop position by hydraulic means controlled by a pilotvalve II4. This pilot valve has a plunger II5, the beveled end II6 of which is engageable by a latch dog II1 duringupward movement of the ram for shifting the plunger to the right, and thereby into a position to cause bydraulic shifting of the valve plunger to a stop position. This is accomplished in the following manner.

The valve I I4 has a pressure port 8 which is supplied by pump 61; a second port II9 which is connected by channel I to the left end of valve II2; a third port I2I which is connected by branch I22 to the return channel 15; and a fourth port I23 which is connected by channel I24 to port I25 of the stop valve II2, which port is positioned such a distance from the end of the valve thatafter admission of fluid pressure to channel I20, and movement of plunger II3 into its stop position, the port 125 will open and permit escape of fluid into channel I24 and thereby to the right hand end of pilot valve 4 to cause repositioning of the plunger II5 to the position shown in Figure 5. The repositioning of the plunger I I5 will simultaneously close the pressure port H8 and thereby prevent pressure building up in the end of valve housing II2 to such an extent that it will cause further movement of the plunger I I3.

To insure proper positioning of the plunger I I5, a spring pressed detent I28 is provided which is adapted to engage V-shaped notches I21 formed in the periphery of. the plunger. It will now be apparent that when the plunger H5 is shifted toward the right the annular groove I28 will disconnect the exhaust port I2I from port H9, and connect the latter to pressure port II8 whereby fluid will flow to shift the stop valve to a stop position, and the continued flow of the fluid into theright hand end of valve I I4 will immediately cause repositioning of the plunger H5 and close the pressure port II8. Although it would seem that this cycle of action would take place in such a short period of time that the plunger would reengage the end of the trip dog, it is desired to point out that the pump 61 has a sufficiently small displacement that an appreciable period of time is necessary before this action is completed and in addition, the ram has a certain amount of coast so that no interference actually occurs. It will be noted that the entire supply of fluid for the pilot circuits is delivered by the pump 61 and since this pump has a constant displacement per unit of time it can readily be determined just what period of time will be consumed in shifting any one of the manycontro'l valves.

The main operating circuit which controls the flow of fluid to the ram and table cylinders is supplied with fluid pressure from an independent pump I29. This pump has an intake I30 through whichfluid is drawn from the reservoir I3I, and a delivery channel I32 through which fluid is delivered to annular groove I33 formed in the relief valve I34. A channel I35 connects the pump to a pair of pressure ports I36 and I31 of the stop valve. This valve has an annular groove I38, which, in the normal running position of the valve, connects pressure port I36 to port I39, connected by channel I40 to pressure port I4I of the table controlled valve 60. The circuit, as shown, is conditioned to cause downward movement of the broaching ram which means that the table controlled valve plunger 86 is in its right hand position whereby an annular groove I42 connects the pressure port I4I to port I43 which is connected by channel I44 to port I45 of the ram controlled valve 28.

The plunger 6I of this valve is also in its right hand position whereby the port I45 is connected by annular groove I46 .to port 23 whereby the pressure fluid will flow through channel 22 to the lower chamber 2I of the ram cylinder and cause downward movement of. the ram. The fluid returning through channel 24 to port 25 is directed by annular groove I41 in valve plunger I 6I, to port I48 and connected channel I49. The latter terminates in port I50 of the table controlled valve 60, which port is connected by annular groove I5I to port I52 and channel I53. The latter terminates in port I54 of the stop valve which at this time is connected by annular groove I55 in the stop valve plunger to channel I58 which terminates in port I51 of a low pressure relief valve I58. The relief valve has a plunger I59 on which is formed a spool portion movable relative to port I51, and, in which is drilled a radial passage I60 intersecting an axial bore I 6I in the end of which is fitted a plunger I62.

This plunger terminates in an enlarged head located beyond one end of the plunger I59, and this head acts as a spacer between the end of the plunger and a fixed abutment I63, and the parts are normally held in this position by a spring I64 acting on the opposite end of plunger I59. The fluid returning through channel I56 passes through the radial and axial bores I80 and I8I .creating sumcient pressure to cause shifting of the valve plunger I59 to the left thereby uncovering port I51 and permitting fluid to escape past the tapered end I85 of the valve spool to the exhaust port I86 whereby the fluid can return through channel I61 to reservoir.

Attention is invited to the fact that when the plunger I59 is shifted to the left, some of the escaping fluid will be drawn through branch I68 and check valve I69 into the space I10. When the pressure in the axial bore I6I drops and the spring I84 shifts the plunger toward the right, the fluid in the space I10 is put under pressure and retards this movement. This fluid must be forced through the hydraulic resistance "I to reservoir in order that the return movement of the plunger I59 may take place, and the amount of time will be determined by the value of. the resistance. This resistance is sufficiently high to cause the valve plunger I59 to be a fast opening and slow closing relief valve.

The broaching ram continues its downward stroke until the trip dog 83 shifts the plunger 63 of pilot valve 62 to the left which thereby will connect pressure port 66 to channel 12 and cause shifting of valve plunger 6| to its left hand position. In this new, position, the annular groove I26 will connect port 23 to port I12 which is connected by channel I13 to port I14 of the table controlled valve. Since this last named port is closed, return flow from the ram cylinder will not take place.

The annular groove I41 interconnects ports I45 and I48 whereby the pressure fluid entering port I46 will be directed into channel I49 and its branch I15. The branch I15 terminates in port I16 which is now connected by annular groove I11 to port 51, whereby the pressure fluid will flow to the right hand chamber 36 of the table cylinder. The other end of the cylinder is connected through channel 54 to the exhaust port I18 of the ram controlled valve by annular groove I19 which intercouples port I18 with port 58. Port 25 through which fluid pressure was being supplied to the lower end of the ram cylinder is now connected by annular groove I80 to port I8I which is connected by channel I82 to port I83 of the table controlled valve. This last named port is closed and therefore no movement of the ram will take place.

It will be noted that the fluid pressure which was being supplied to port I45, is now directed to the table cylinder; and the opposite end of that cylinder is connected to reservoir whereupon the table will be retracted from a cutting position. At the end of the table stroke, the dog I05 will shift the pilot valve plunger 88 and connect pressure port 94 to channel 99 and thereby shift the table controlled valve plunger 86 into its left hand position. This will cause the pressure port I4I to be disconnected from port I43 and connected to port I83, and at the same time, will position the annular groove I84 so as to interconnect port I14 with exhaust port I85. Since port I83 is now connected through valve 26 to the upper end of the ram cylinder and the lower end of the ram cylinder is connected to reservoir, the ram will start its upward movement.-

When the ram has nearly completed its upward stroke, the latch dog II1 shifts the pilot valve plunger I I5 to the right thereby connecting pressure port II8 to the left hand end of the stop valve, shifting the plunger II3 thereof into a stop position in the manner previously described. This causes the annular groove I38 to interconnect the pressure port I36 of the stop valve to the return port I86 whereby the pump I29 becomes short-circuited to reservoir. At the same time the spools I81, I88 and I89 of the plunger II3 will close ports I39, I31 and I90 respectively.

This will prevent escape of hydraulic fluid from now shift the ram'controlled valve plunger into right hand position While the table controlled valve plunger 86 is still in its left hand position. Fluid pressure which is still being delivered to port I8I at this time is now connected through annular groove I to port 58 and thereby through channel 54 to the left hand end of table cylinder 28 causing the same to advance to a cutting position, and since ports I43 and I50 are closed, no movement of the broaching ram will take place. Return fluid from the chamber 36 of the table cylinder will pass through channel 53, port I16, annular'groove I19 and port I18 to the return channel I9I which is connected at this time through port I92 of the stop valve, annular groove I93 and port I86 to the return channel I68.

After the table completes its advancing movement, the locking lever 4|, as it moves into looking position, causes the dog I06 carried thereby to shift the pilot valve plunger 88 to its right hand position, as shown in Figure 5, whereby fluid will be admitted to the' left hand end of the table controlled valve and shift the plunger thereof into its right hand position. This will disconnect the pressure port I4I from port I8I of the ram controlled valve and connect it to port I45 thereof, whereby fluid will now be delivered through channel 22 to the lower end of the ram cylinder causing downward movement thereof. The cycle now repeats itself. M

If it is possible for the operator to reload the work fixture duringthe time that the ram is moving upward on its return stroke, the stop dog I I1 can be eliminated, whereby the machine will operate continuously.

For set-up purposes and the like the stop valve plunger II3 may be manually moved to a reverse position which will thereby connect the pressure port I31 to port I54 and connect port I39 to a return port I 94 whereby the flow in channels I40 and I53 will be reversed and reversal in the movement of the parts will take place. There has thus been provided an improved broaching machine having improved automatic means for positioning a work piece with respect to a broaching tool and which is simple in construction and operation.

What is claimed is:

1. In a broaching machine having a broaching ram and a work table, the combination of hydraulic means for shifting the table to a cutting position relative to the ram, means for positively stopping the table in said position and thereby causing a reaction on said hydraulic means, and means responsive to said reaction and positionable thereby to prevent return movement of the table during the cutting operation.

2. In a broaching machine having a reciprocating broaching ram and a work table, the combination of fluid operable means for shifting the table toward the ram, a positive stop for limiting said movement, means to lock the table against said positive stop, including a member yleldable to the reaction on said hydraulic means caused by engagement of the table with said stop, and a table locking member responsive to movement of said yieldable member.

- 3. In a broaching machine, the combination of a broaching ram having a cutting tool attached thereto, a support, a reciprocable, work table mounted thereon, a pair of fluid pressure separable parts for causing movement of the table, one of said parts being fixed to the table and the other carried by the support, a positive stop for limiting movement of the table toward the ram, and thereby acting as an abutment for one of said parts, means effective upon engagement with said stop to release the other part for movement by the fluid pressure, and means responsive to said movement to lock the table against said positive stop.

4. In a broaching machine having a broaching ram, 2. support and a work table movable on thesupport froma loading position to a cutting position, the combination of means for moving the, table from one position to the other, including a pair of cooperating parts adapted to be separated by fluid pressure, one of said parts being attached to the. table, means to mount the other part on the table support, a swinging lever operatively connected to the last named part, means to supply fluid pressure to cause separation of said parts, means to prevent rotation of said lever to thereby cause movement of the table, and means operable upon completion of table movement'to release said swinging lever whereby continued action of said fluid pressure will cause said lever to lock the table.

5. In a broaching' machine having a broaching I named member whereby upon admission of presa locking lever for positively holding the table in the cutting position, a source of fluid pressure for causing reciprocation of the ram, a control valve, a pilot circuit, including apilot valve for controlling the shifting of said control valve, and means trip operable by the locking lever during movement into table holding position for shifting said pilot valve into a position that will cause said main control valve to assume a position that will connect said fluid pressure for operation of said ram.

7. In a broaching machine having *a broaching ram and a work table, the combination of fluid operable means for shifting the ram and the table respectively, a main control circuit including a source of fluid pressure, valve means for alternately connecting said source to said fluid operable means, an independent pilot circuit for effecting fluid shifting of said valve means, including a metering pump and individual pilot valves associated respectively with the ram and the table, means for tripping said pilot valves from the moving supports, said metering pump being of sufficiently small volume whereby a slight delay occurs between tripping of said pilot valves and the shifting of said valve means whereby the moving supports may complete their movement before the next action takes place.

8. In a machine tool having a reciprocating slide, the combination of fluid operable means for shifting said slide, a source of fluid pressure therefor, a stop valve, a pilot circuit for shifting said stop valve from a running position to a stop position, including trip operable means for connecting fluid pressure to said pilot circuit, and means to utilize said fluid pressure after the stop valve has been shifted to causerepositioning of the trip operable means.

9. In a machine tool having a fluid operable slide and fluid pressure means for actuating said slide, the combination with a stop valve interposed between said fluid operable means and said fluid pressure means, of a trip plunger, means carried by the slide for shifting said plunger, power means operable by said plunger for causing shifting of said stop valve, and means responsive to completion of the shifting movement of said stop valve to automatically reposition said trip plunger.

10. In a machine tool having a fluid operable ram, a source of fluid pressure, and a valve for controlling the coupling of said fluid pressure to theram, the combination of a fluid operable pilot circuit for shifting said valve from one position to another, manually operable means for shifting said valve, and means to automatically release the fluid after effecting a shifting of the valve and thereby condition thevalve for immediate manual operation.

11. In a machine tool having a work support and a tool support, the combination with power operable means for effecting relative movement between the supports, of a stop mechanism, fluid pressure means for actuating said stop mechanism, manually operable. means for actuating said stop mechanism, and means to automatically release said fluid pressure after-actuation of said stop means to thereby reinstate said manual control.

12. In a machine tool having a work support, and a tool support, an hydraulic control circuit for alternately moving said supports, including fluid operable motors for actuating the respective supports, a first control valve having a pair of pressure receiving ports and separate pairs of channels extending to each of said motors, a pilot circuit for controlling the shifting of said valve including trip dogs carried by one of said supports, a second valve for alternately coupling said pressure receiving ports to a source of pressure, a pilot circuit for governing the shifting of said second valve, means trip operable by the other of said slides for controlling said last named pilot circuit, a stop valve, fluid operable means controlled by the flrst named slide for causing shifting of said stop valve to a stop position, and manually operable means for repositioning said stop valve in a running position.

13. In a broaching machine having a broaching ram and a work support, the combination of means for shifting said work support to a cutting position and locking the same in said position, including a piston and cylinder, the latter being integral with said work support, positive stop means for determining the cutting position of said table, a piston rod integrally connected to saidpiston and supported for limited axial movement, a bell crank having a bifurcated connection with said piston rod, a locking lever,

a locking abutment, carried by the table, said abutment riding on said locking lever during movement of the table to prevent rotation thereof caused by reaction of the fluid pressure on said piston in moving the table, said lever being of such length that the abutment will clear the end of the lever when the table hits the positive stop whereby the lever may move into endwise engagement with the block to prevent return movement of the table during a cutting operavalve to initiate movement of the breach ram.

.15. A control mechanism for a broach or the like of the. type including a support, a breach ram reciprocable on the support and a work holder movable into and out of operative rela- .tion with respect to the ram, said control mechanism including a hydraulic circuit for actuation of the broach ram, an actuation controlling valve therefor, a second hydraulic circuit for eflecting movement of the work holder, a locking member actuable by said circuit for securing the holder in operative position, means actuable by movement of the locking member" for shifting said valve to initiate movement of the broach ram, a main control valve efiective as respects both of said circuits, a ram controlled hydraulic actuator therefor, means on the ram for effecting one direction of movement of said actuator, and means activated by movement of the valve for effecting reverse shifting of the actuator.

16. In a machine of the character described,

the combination with a hydraulically reeipro cable broach carrying ram and a work holder movable toward and from the ram, of a reversing valve for determining the alternate directional movements of the holder, cooperating trip elements associated with the ram and valve for effecting reversing positions of the latter, a power circuit controlling valve having stop and actuating positions, an actuation control valve for determining power shifting thereof to stop position and uni-directionally eflective trip means associated with the ram and actuation control valve disposed to actuate the latter to shift the main valve into stop position at 'an intermediate point in the stroke of the ram.

17. In a machine of the character described,

the combination with a hydraulically reciprocable breach carrying ram and a work holder movable toward and from the ram, oi a reversing valve for determining the alternate directional eiiecting reversing positions of the latter, a power circuit controlling valve having stop and actuatingpositions, an actuation control valve for determining power shifting thereof to stop position and uni-directionally eflective trip means associated with the ram and actuation control valve'disposed to actuate the latter to shift the main valve into stop position at an intermediate point in the stroke of the ram, and means .controlled by movement of the main valve into stop position for repositioning the trip operated actuation control valve.

.18. In a machine of the character described, the combination with a hydraulically reciprocable broachcarrying ram and a work holder mov able towards and from the ram, of a first piston and cylinder mechanism for actuation of the ram a second piston and cylinder mechanism for actuation of the work holder, one of said last-named parts being supported for floating movement, a hydraulic circuit for effecting actuation of the respective piston and cylinder mechanisms including a first'ram actuable reversing valve .for determining talble' movements, trip means on the ram for effecting opposite movements of said valve as the ram approaches its its limit of movement in one direction, meansactuable by movementof the member into locking position for shifting the ram actuation controlling valve, a stop valve effective as respects both ram and work holder, temporarily energizable means for efiecting power shifting of said valve to a stop position, and uni-directionally effective actuating means therefor carried by the ram and disposed to actuate the stop valve at an intermediate point in the movement of the ram, substantially as and i'or'the purpose described. T

EDGAR n. vANCIL. AMOS H. HAWLEY, SR. 

